1. Field of the Invention
The present invention relates to a sheet feeding apparatus for an electrophotographic device and, more particularly, to a multi-functional sheet feeding device that can intersperse a manually fed document between documents that are being loaded from a separate tray using an automatic document loading process.
2. Background Art
An image formation apparatus (e.g., a printer, scanner, facsimile or copier) must often accommodate printable mediums having a thickness or dimensions different from that of standard paper. Envelopes, postcards, transparencies, labels and resume paper are just a few examples of the different printable mediums that a sheet feeder must accommodate. A sheet feeder may be constructed to use a tray that supplies paper to a printer. The tray often has an adjustment lever allowing the paper to be moved away from a pickup roller in order to load additional sheets of paper into the tray. After loading additional paper, the adjustment lever is moved in a direction opposite that used for preparing the tray to receive additional paper causing the pickup roller to press against the paper on the tray and then transfer the paper to a transfer roller. Then, the transfer roller transports the sheet of paper to the printer cartridge.
Contemporary image forming devices use one of two kinds of methods to feed sheets into a printer or scanner. One method is to use an automatic paper feeding device that continues to load a multitude of papers as required by a controller. The second method of loading a document is to load the document manually. This normally requires that a user either replace the stack of papers normally being automatically loaded by the computer with the document to be loaded or that the user stop the printing process and position the document on top of the stack of papers currently being used for automatically feeding paper into the image forming or reading device. Having to stop the printing or scanning process of an imaging forming or recording device to change the medium that the device uses can be very inconvenient to a user, results in the waste of time, and thus lowers the printing or recording efficiency of the electrophotographic device.
As such, I believe that it may be possible to improve on the contemporary art by providing a multi-functional sheet feeding device that can intersperse a manually fed document between documents that are being loaded from a separate tray using an automatic document loading process, that reduces the number of components normally required to build sheet feeding device capable of both printing automatically or using a manually fed document from a second tray, that increases the productivity of a user by eliminating the need to stop the automatic sheet loading process to manually feed a document, that is simple to manufacture, and that is economical to produce.